1. Field of the Invention
The present invention relates to a method of producing a metal plated material, a metal plated material, a method of producing a metal pattern material, and a metal pattern material.
2. Description of the Related Art
Conventionally, substrates having wiring including a metal pattern formed on a surface of an insulating support (metal pattern material) have been widely used for electronic members or semiconductor devices.
The metal pattern material is mainly produced by a “subtractive method”. The subtractive method includes forming a photosensitive layer, which is sensitized by irradiating with actinic rays, on a metal film formed on a surface of a substrate; exposing the photosensitive layer to light in an image-wise manner; developing the photosensitive layer to form a resist image; etching the metal film to form a metal pattern; and peeling off the resist from the metal pattern.
In the above method, the substrate and the metal film are tightly adhered to each other by means of an anchoring effect generated by providing irregularities on the surface of the substrate. Therefore, there is a problem in that high frequency characteristics of metal wiring including the metal pattern may deteriorate due to the irregularities of the metal pattern at an interface with the substrate. Further, since the surface of the substrate needs to be treated with a strong acid such as chromic acid for roughening, it is necessary to perform a complicated process in order to obtain a metal pattern having excellent adhesiveness between a metal film and a substrate.
In order to address the aforementioned problem, Japanese Patent Application Laid-Open (JP-A) No. 11-12504 proposes a method including forming a cured layer containing a polymer having a chelating ligand capable of trapping metal ions that serve as a plating catalyst, and plating the cured layer. In this method, a composition prepared by mixing the polymer and a curable agent is used for the formation of the cured layer. However, the stability over time of the compound prepared by the above process may be insufficient, and the compound may not form a uniform cured layer. Further, all examples of the chelating ligand disclosed in JP-A No. 11-12504, including carboxylic acid-type ligands represented by iminodiacetic acid, azo-type ligands, polyamine-type or polyimine-type ligands, alcoholic or phenolic hydroxyl-type ligands, and β-diketone-type ligands, are hydrophilic. Therefore, there are problems in that absorption or desorption of moisture tends to occur due to changes in humidity or temperature, or the metal film tends to exfoliate from the substrate. Moreover, when the metal pattern material obtained by the above method is used for wiring of the metal wiring substrate, a graft polymer having a polar group remains at an interface with the substrate to promote retention of moisture or ions. Therefore, there are concerns regarding unfavorable influence of temperature or humidity, resistance to ion migration between the wiring, or deformation of the wiring lines. In particular, when the metal pattern material is used for fine wiring of a print wiring substrate or the like, insulating properties between wiring (metal pattern) lines need to be improved. Accordingly, further improvement in reliability of insulating properties among the wiring is demanded.